A rare total lunar eclipse is happening today, June 15, and will be visible in parts of South America, Europe, Asia, Australia, and Africa.
The event will be the longest lunar eclipse in 11 years, beginning at 1:24 p.m. EDT (17:24 GMT) and ending at 7 p.m. EDT (23:00 GMT). During this time, the Earth’s shadow will completely cover the moon for one hour and 41 minutes.
The moon will change color as it moves deeper into the Earth’s shadow, changing from gray to orange or possibly deep red.
According to Spaceweather.com, ash clouds from the recent Chilean Puyehue-Cordón Caulle volcanic eruption could create an even darker shade of red.
NASA’s Lunar Reconnaissance Orbiter (LRO) spacecraft will zoom in during this celestial phenomenon, allowing people in North America, where it won’t be visible, to see a digital version instead.
LRO’s Diviner Lunar Radiometer will determine how quickly certain areas of the moon’s day side cool off due to the eclipse.
“This is an unprecedented opportunity to learn more about the uppermost few millimeters of the moon,” says Diviner Principal Investigator David Paige at the University of California in a press release.
Diviner will target 10 sites during the entire eclipse period to study how a diverse selection of lunar terrains responds due to the sudden drop in temperature.
“Some consist of fine dust, others are rocky, and there are a variety of compositions including dark, iron-rich lunar maria and light, iron-poor lunar highlands,” says Noah Petro at NASA’s Goddard Space Flight Center in Greenbelt, Md, in the release.
“The moon turns slowly—a complete day-night cycle lasts more than 29 Earth days,” adds Petro. “So lunar dusk and dawn last a long time, and normally the lunar surface cools down and heats up slowly. This eclipse is a special opportunity to see what happens if you ’switch off' the sun relatively quickly.
“It’s like taking a pie out of the oven and throwing it into the freezer without letting it cool down first,” explains Petro. “We want to see how the moon’s surface responds to this abrupt temperature change.”
